Google Inc.’s YouTube unit was sued by David Grisman, a mandolin player who once performed with the Grateful Dead, over what he says are unauthorized postings of his music, the latest suit against the popular video-sharing site.

Grisman, his partner Craig Miller and their company Dawg Music sued Google and YouTube May 10 in federal court in San Francisco. They are seeking to represent other musicians and copyright owners whose works are posted on the site without permission or compensation.

Google, the most-used Internet search engine, and its YouTube site already are facing a $1 billion copyright-infringement suit from Viacom Inc., owner of Comedy Central and MTV Networks. Lawsuits also were filed by England’s top-tier soccer league; the music publisher Bourne Co., owner of the copyright to the 1972 instrumental hit “The Popcorn Song”; and the man who videotaped the beating of a trucker during the 1992 Los Angeles riots.

YouTube has a “massive arsenal of misappropriated copyrighted material” and a “deliberate strategy” to promote copyright infringement, the complaint contends.

The suit seeks cash to compensate copyright owners for past infringement and a court order to force YouTube to change the way it does business. Company spokesman Ricardo Reyes didn’t immediately reply to an e-mail message seeking comment.

Google and YouTube “pay lip-service to a purported desire to avoid violating intellectual property laws,” the complaint says. “In reality, however, they deliberately refuse to take meaningful steps to deter the rampant infringing activity readily apparent on YouTube which would, in turn, have a negative impact on the advertising and other reviews and other value achieved through the large volume of traffic on the YouTube Web site.”

Grisman, who specializes in acoustic music, recorded and toured with Jerry Garcia, the late frontman for the Grateful Dead.

The May 4 suit filed by England’s Football Association Premier League Ltd. and Bourne also are seeking class-action status to represent other copyright owners. That suit, and the one by Viacom, was filed in federal court in New York.

Google, based in Mountain View, bought YouTube for $1.65 billion last year.

Earlier, in response to the Viacom suit, Google said YouTube is protected by a U.S. copyright law exemption of online services from claims stemming from the actions of their customers. YouTube obeys the law by removing material that infringes copyrights when owners protest, Google said.

Shares of Google fell $4.96 to $461.78 in Nasdaq Stock Market composite trading. They are little changed this year, leaving the company with a market value of $143.9 billion.